Failed idleness check due to log_timezone other than UTC

I'm getting errors like this one in the logs of the dblab_server container:

2023/01/09 08:02:01 [ERROR] Failed to check the idleness of clone emil-1: failed to get the last session activity: failed to get the time of last activity: failed to parse the last activity time: parsing time "2023-01-08 12:03:44.275 CET" as "2006-01-02 15:04:05.000 UTC": cannot parse "CET" as " UTC".

The clone was created with --extra-config log_timezone='Europe/Stockholm'. The expected behavior is that the idleness-check handles any timezone that Postgres is configured with.